Drill-bit.



G. AI HUMAS ON.

DRILL BIT.

APPLICATION FILED SEPT. 8. R15.

Patented July 18, 1916.

2 SHEIETSSHEET 1.

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Witnesses Q Inventor At'torneys G. A. HUMASON- i DR-ILL BIT.

V APPLICATIO EPT.8 m 1,191,310; Patented July 18,1916.

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\Ni't ssss es nventor GRANVILLE A. HUMASON, 0F SHREVEPORT, LOUISIANA.

DRILL-BIT.

Specification of Letters Patent.

Patented July 18, ieic.

Application filed September 8, 1915. Serial No. 49,566.

To all whom it may concern:

Be it known that I, GRANVILLE A. HUMA- soN, a citizen of the United States, residing at Shreveport, in the parish of Caddo and State of Louisiana, have invented a new and useful Drill-Bit, of which the following is a specification. v

This invention relates to drill bits, one of its objects being to provide means whereby the cutters of the-bits can be readily detached and others substituted. y I

The structure is more especially designed for use in connection with bits of that type utilizing inclined side cutters and horizontal end cutters for use in cutting rock or gumbo. I a 1 Heretofore where inclined side cutters have been used the inner edges of the cutters have tended to become worn after long continued use and considerable difliculty has been experienced insubstituting new cutters.

As before stated, one of the objects of the present invention is to provide means where by the cutters of the bits can be readily detached and replaced or others substituted, the parts provided. forholding the cutters in place 'being'simple and dnrable in construction and being so assembled as not to come apart while the bit is in use.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood .tion of the drill bit embodying the present improvements. Fig. 2 is. another elevation of the said bit viewed at right angles to.

Fig. 1, Fig. 3 is an enlarged section on rotation.

line AB Fig. 1. Fig. 4 is a central longitudinal section through one of the holding plates of the bit. Fig. 5 is a similar view of another one of the holding plates. Fig. 6 is an elevation of the bearing of the horizontal cutters. Fig. 7 is a side elevation of one of the bearings of the side cutters. Fig. 8 isan end view of the bearing shown in Fig. 7.

Referring to the figures by characters of reference 1 designates the head of the bit having its upper end reduced and threaded,

as shown at 2. Formed within the outer surface of the head are longitudinallly ex-- tending dovetail grooves-3 preferably equidistant as shown in Fig. 3.

Inwardly converging recesses 4 formed in opposed portions of the head at the lower end thereof and two of the grooves 3 lead to these recesses. These two grooves are adapted to receive tongues 5 which are dovetail and the lower ends of which are beveled, as at 6, so as to be parallel with the opposed walls of the recesses 4, the lower end portions of the tongues 5 thus constituting the outer side portions of the recesses.

Each tongue 5 has an inwardly extending shoulder 7 adapted .to extend under and to abut against an inwardly extending shoulder 8 at thelower end of the groove 3 in which the tongue is seated, so that upward thrust against the tongue 5 is thus communicated to the head .1. Tongue 5 is held tov the head by means of screws 9 fitted within counter bore openings 10. Formed in the lower end portion of each tongue 5 is an opening 11 having arecess 12 in the outer portion of the wall thereof. This opening is designed'toreceive a bearing pin 13 provided with a lug 14 adapted to occupy the recess 12and thus to hold {the pin against Said pin is extended at right angles to the beveled face 6 vof the tongue and has a split recessed end 15 which extends into a tapered opening 16 in the inner wall of recess 4,'this wall dividing the recess 4 from a central end recess 17 in the head of the bit. The pin 13 is held in position across the recess lby inserting an expanding screw are 18 into the recess in the split end of pin 18 with the result that said end will be eX- panded in the tapered opening 6 and pin 13 held securely against withdrawal; Mounted on each pin 13 ;is an inclined cutter 19 which can be of any desiim germ. For example, in the drawings a toothed cutter has been'shown but it is to be understood that concavo-convex disks for use in cutting gumbo, or any other suitable forms of side cutters can be employed. Obviously by' removing the screws 18 the split ends of the pins 13 are free to contract and said pins can thus be withdrawn outwardly from the openings 16 and 11, thus releasing the side cutters 19.

'The ends of the recess 17 are open an the remaining dovetail grooves 3 in the head lead to these open ends of the recess. These last mentioned grooves 3 are adapted to receive dovetail tongues 20 having counter bored openings 21 for. the reception of holding screws 22 whereby thetongues are fas-- tened to the head. Formed within the lower end portions of the tongues are angular openings 23 and extending inwardly from.

sired to remove the horizontal cutters 27, it ismerely necessary to detach one or both of the tongues 20 from the head 1, whereupon the pin 26 will be released and the cutters can be removed from the pin and replaced or new cutters can be placed in posi tion.

Importance is attached to the fact that all of the tongues have means for transmitting end thrusts against the head 1, thus relieving the fastening screws of all strains during the operation of the bit. Furthermore, the ease with which the various cutters can be removed frem and placed in posi tion is important as i's also the fact that cutters of different types can be assembled with the bit herein described.

1 V hat is claimed is:

1. A drill bit including a head having a groove, a tongue detachably mounted within the groove and retained by the walls thereof, means upon the tongue and cotiperating with the head for transmittinglongitudinal thrust from the tongue to the head, a bear- It willbe obvious that whenever it is de-.

ing pin detachably engaging the tongue, and a cutter carried by the pin.

2. A drill bit including a head having a dovetail groove, a dovet'ail tongue seated in with the head for transmittlng longitudinal thrusts from the tongues to the head, bearing pins having their outer ends detachably engaging the respective tongues and their inner ends engaging the head, and cutters mounted on the-bearing pins.

4. In a drill bit the combination with a head having inwardly converging side recesses,.there being longitudinal grooves in the outer face of the head and communicating with the recesses, of tongues detachably secured in and lapped and retained by the walls of the grooves and constituting the outer side walls of the side recesses, means upon each tongue and codperating with the head for transmitting longitudinal thrust from the tongue to the head, bearing pins detachably engaged by the tongues, and cutters mounted on the pins.

5. In a drill bit the combination with a head having inwardly converging side recesses, there being longitudinal grooves m the outer face of the head andcommunicating with the recesses, of tongues detachably secured in the grooves and constituting the outer side walls of the side recesses, means upon each tongue and cooperating with the head for transmitting longitudinal thrust from the tongue to the head, bearing pins detachably engaged at their ends by the tongues, each of said pins having expansible inner ends, means engaging'said inner ends to expand them within the walls of the end recess, and cutters mounted on said pins and within the respective side recesses.

6. In a drill bit the combination with a head having inwardly converging side recesses and longitudinal grooves opening into the recesses, of tongues detachably secured within the grooves and having their lower end portions constituting the outer side walls of the converging recesses, each tongue having an opening therein provided with a recess in the wall thereof, there being a tapered opening within the inner 'wall of each of said inwardly converging recesses, bearing pins extending transversely of the inwardly converging recesses and .within the openings in, the tongues, projections upon said pinsnnd the "rocss es in tho as my' own,I hnvehereto affixed signatongues, eah -p1n havlng an expansible end ture in the presence oftwo WltHBSSQS.

means for expanding said nd withln said seglted within ,the adjaeent tapered opening, GRANVILLEA. HUM

. opening, and a gutting element mounted on Witnesses:

each pin. 7 v JAMES DfMnAnows; lnitestimony thatil c1aim. the foregoing i J. AIKEN, 

